MicroRNA regulating metabolic reprogramming in tumor cells: New tumor markers

Abstract

Metabolic reprogramming is a feature of cancer cells that provides fast energy production and the abundance of precursors required to fuel uncontrolled proliferation. The Warburg effect, increase in glucose uptake and preference for glycolysis over oxidative phosphorylation (OXPHOS) as major source of energy even in the presence of oxygen, is the main metabolic adaptation of cancer cells but not the only one. Increased glutaminolysis is also observed in cancer cells, being another source of adenosine triphosphate production and supply of intermediates for macromolecule biosynthesis. The ability to shift from OXPHOS to glycolysis and vice versa, known as metabolic plasticity, allows cancer cells to adapt to continuous changes in the tumor microenvironment. Metabolic reprogramming is linked to the deregulation of pathways controlled by hypoxia-inducible factor 1 alpha, MYC, or p53, and microRNAs (miRNAs) have emerged as key regulators of these signaling pathways. miRNAs target metabolic enzymes, oncogenes, and tumor suppressors involved in metabolic reprogramming, becoming crucial elements in the cross talk of molecular pathways that promotes survival, proliferation, migration, and consequently, tumor progression and metastasis. Moreover, several miRNAs have been found downregulated in different human cancers. Due to this fact and their central role in metabolism regulation, miRNAs may be considered as biomarkers for cancer therapy.